Advances in digital photography have resulted in the incorporation of digital cameras in a variety of devices. For example, many portable electronic devices now include integrated digital cameras. Devices into which digital cameras have been integrated include, for example, cell phones, smart phones, personal digital assistants (PDAs), laptop computers, monitors, and tablet computers, among others. Furthermore, digital cameras are increasingly being incorporated into vehicles and other goods. In this regard, the prevalence of integrated digital cameras in devices continues to increase.
Digital cameras generally operate by exposing an image sensor to light. The image sensor produces electrical signals in response to light striking an active area of the image sensor. The electrical signals are interpretable as digital image files that may, for example, be stored or displayed. Examples of types of image sensors include, for example, CCD sensors, CMOS sensors, and sCMOS sensors.
Regardless of the specific type of image sensor used, “particle drop” is an issue common to all digital camera image sensors. Particle drop refers to when particles (e.g., originating from within the camera module or from an exterior environment) become disposed relative to the image sensor so as to interfere with the operation of the image sensor (e.g., obstructing the path of light to the image sensor causing blemishes, dark spots, or other flaws on images captured by the image sensor). Particularly in the case of integrated camera modules that are sealed or where the image sensor is inaccessible, prevention of particles from entering the optical path of the sensor is important to maintain the quality of images generated by digital camera modules because the image sensor cannot be accessed to be cleaned or cleared of particles. Additionally, as image sensors become smaller, the sensitivity to particle drop increases as even small particles may act to block more pixels of the active area of the image sensor. As such, addressing the particle drop issue continues to be important to maintaining the quality of images captured with digital cameras.